1. Field of the Invention
The present invention relates to automobile windshields. More particularly, the present invention relates to cleaning and protecting automobile windshields.
2. General Background of the Invention
Acid rain causes spots on automobile windows and windshields which are difficult to remove. One commercially available method of removing these spots involves rubbing the glass with a piece of clay (see, for example, products sold under the trademark CLAY-MAGIC, U.S. Trademark Registration No. 1,890,761). However, this is a difficult job, is typically only done professionally, and is not in widespread use.
Glass and glass windshields get contaminated with acid rain spots and by mineral deposit from the rain. These contaminants are mostly impossible to remove, except by fairly drastic professional treatment. This often involves grinding away the deposits with a machine buffer utilizing abrasive compound. This not a job for the “do-it-yourselfer”. It is very easy to permanently scratch the glass, ruining the windshield.
It is known in the automotive aftermarket trade that kaolin clay can remove mineral deposits from painted automotive surfaces if properly applied. This involves dragging a solid block of clay across the paint using a soapy water solution as a lubricant. This prevents scratching and prevents drag. However, the process is somewhat difficult and requires a higher skill level. If the bar is not rotated frequently, the accumulated contaminant will quickly scratch the finish. It is a process that does not lend itself to glass. Kaolin clay by itself will not scratch the glass since the material is softer. The mineral deposits are, however, much harder.
Kaopolite SF (super fine kaolin clay) has been used for many years in car polishes for painted surfaces.
Fibershield 218, commercially available from Fibershield Industrials, is a coating for aircraft windows to help them repel rain, making it sheet. Fibershield 7525 is a similar coating.
A web site sponsored by PPG tells about their product “Aquapel”. It appears to be the same type of chemistry as Fibershield 218. However, it is applied using a special sponge applicator. The PPG product is for professional use so the inventors believe that it is the standard water-based product that requires buffing clear. Aquapel makes no claims as scratch resistance. They also make no claims about treating acrylics (either Plexiglas or polycarbonate).
The following U.S. patents are incorporated herein by reference: U.S. Pat. Nos. 4,051,056; 4,338,377; 4,395,456; 4,450,151; 4,687,591; 5,034,114; 5,076,952; 5,128,027; 5,712,355; 5,779,912; 5,846,650; 5,872,111; 5,928,064; 5,969,067; 6,156,389; 6,177,196; 6,183,872; 6,207,780; 6,241,579; and 6,310,014.
U.S. Pat. No. 4,687,591 discloses an aerosol cleaning composition with 15–25% by weight kaolin clay for cleaning cymbals.
U.S. Pat. No. 4,450,151 discloses an aerosol composition which could contain 5–60% by weight kaolin clay.
U.S. Pat. No. 5,076,952 discloses a liquid dishwasher cleaning agent which can contain clay particles, sodium bicarbonate and sodium tripolyphosphate.
U.S. Pat. No. 4,395,456 discloses an inorganic foam which can include kaolin clay.
U.S. Pat. No. 5,034,114 discloses neutralizing acid with a solution containing sodium bicarbonate and a detergent tripolyphosphate.
U.S. Pat. No. 6,241,579 discloses a surface polishing applicator system and method. U.S. Pat. No. 5,928,064 discloses a surface polishing method and system. Both of these patents are assigned to Auto Wax Company, Inc., the maker of Clay Magic brand polish and bars containing abrasive material for removing stains from automobiles.
U.S. Pat. No. 5,846,650 discloses a protective coating for windshields (see column 1, line 9) that prevents ice build-up and contains a fluoropolymer and a fluorochemical surfactant (see column 2, lines 35–42).
U.S. Pat. Nos. 5,969,067 and 6,177,196 disclose a coating solution containing a fluoropolymer, which can be applied to a windshield (see column 7, lines 7 and 8).
U.S. Pat. No. 6,156,389 discloses a protective coating that is applied to windshield and contains a fluoropolymer (see claim 3 in Column 32).
U.S. Pat. No. 5,712,355 discloses a formulation that contains fluoropolymers, fluorosurfactants and water that is applied to glass microscope slides as a protectant.
U.S. Pat. No. 6,183,872 discloses a fluoropolymer coating which apparently chemically bonds to glass (see column 3, lines 35–40).